hash_benchmark.rb

require 'benchmark'
 
class Request
  def initialize(first, last, city, state, country)
    @hash =
    {
      'first'.freeze   => first,
      'last'.freeze    => last,
      'city'.freeze    => city,
      'state'.freeze   => state,
      'country'.freeze => country
    }
  end
 
  def first
    @hash['first'.freeze]
  end
 
  def last
    @hash['last'.freeze]
  end
 
  def city
    @hash['city'.freeze]
  end
 
  def state
    @hash['state'.freeze]
  end
 
  def country
    @hash['country'.freeze]
  end
 
  def to_a
    [first, last, city, state, country]
  end
end
 
result = Benchmark.measure do
  request = Request.new('Colin', 'Kelley', 'Santa Barbara', 'CA', 'USA')
 
  10_000_000.times do
    request.to_a
  end
end
 
puts result

results

Without magic comment:  14.61 seconds
With magic comment:      9.2 seconds           # -*- immutable: string -*-

Immutable string version runs 1.58X faster (runs in just 63% of the time)